Process of converting starch into derivatives, dextrin, dextrose, &amp;c.



s. M. LILLIE. PROCESS OF CONVERTING STAROH INTO DERIVATIVES, DEXTRIN,DEXTROSE, 8w.

APPLIGATIONTILED JAN.14, 1910.

Patented May 24, 1910.

ll IVENTOR:

SAMUEL MORRIS LILLIE, OF PHILADELPHIA, PENNSYLVANIA.

rnocnss or convnnrme s'rnnc r rm'o nnnrvnrrvns, nnxram, nnxu'nosn, 8:0.

959,237. Original application filed February 18,

To all whom it concern:

Be it known that I, SAMUEL Mourns LIL- LIE, a citizen of the UnitedStates, residing at Philadelphia, in the county of Philadelphia andState of Pennsylvania, have invented a new and useful Process ofConverting Starch intojJerivative's, Dextrin, Dextrose, &c., of whichthe following is a specification. t

This a .plication is a division of my application, gerial No. 416,455,filed February 18th, 1908.

The method usually employed for the conversion of starch into thesederivatives is'to nearly fill a closed vessel converter. provided with aperforated steam heating coil with a mixture of starch, water anda'small proportion of acid, heat the mixture under pressure by injectedsteam to the desired converting temperature, say 289 F ah., shut off thesteam and allow the heated mixture to stand until the mass of themixture has.

been converted to the. desired degree as indicated by a reagent, usualla solution of iodin. A discharge valve is t on opened and the contentsof theconverter discharged into a tank open to the atmosphere the vaporsdue to the reduction in pressure passing away into the atmosphere. Theconverter is then recharged with theacid starch mixture and anotherconversion made. Each batch of converted liquor after leavin theconverter is neutralized by a suitab e reagent, as carbonate of soda,for example. The conversion of the starch progresses with the durationof its heated stay in the converter, which if long enough will carry itthrough the several conditions of starch paste, soluble starch, anddcxtrin to dextrose. The charge is kept in the converter until it hasarrived at the desired degree of conversion. The portion of the chargefirst to leave the converter is less converted than the portion whichleaves the converter last, for the latter is subjected to the heat asmuch longer than the former as ittakes to empty the converter, and thetwo show with iodm uite different stages of conversion. This lac ofuniformity in the conversion is one of the faults of this usual methodof converting starch which it is the pur se of my invention to obviate.Another ault of this procsee is the intermittent demand for steam on theboilers. -The converter makes a heavy demand while the charge is beingheated to Specification of Letters Patent.

1908, Serial no. 416,455. Divided 14,1910. Serial No. 538,126.

sired quantity of product in a Patented May 24, 1910. and thisapplication filed January REISSUED the converting temperature and thennone at all until the next charge is heated.

The purpose of my invention is to provide a continuous process ofconverting starch by means of'heat, acid and Water into derivativesdextrin, dextrose, &c., and to obtain a practically uniform conversion,a constant draw of steam from theboilers, and other advantagesincidental to a continuous process.

The process of treating the starch consists in mixing the starch withwater and acid to form a mixture of the desired mobility and acidity inquantities suflicient to supply requirements; in forcing the saidmixture of starch, Water and acid continuously and at a uniform rate offlow, corresponding to the quantity of product Wanted, through suitableheating devices and heatng 1t therein under pressure to the desiredconverting temperature, say 280 degrees Fahr., making this heatingperiod so brief that the starch mixture on leaving it will have sufieredonly'a partial conversion; in delivering this but onlypartiallyconverted heated mixture with an even distribution over the crosssection of a column of the mixture, to which no more heat is added,moving uniformly through a containing vessel in which vessel thepressure is maintained not less than that corresponding to theconverting temperature to which the mixture has been raised;in-withdrawing from the end of the column the the same rate at which itis being deliveredto the column at the opposite end, 71. e., the uniformrate necessary to produce the degiven time; in varying the length ordepth of the said column of mixture to vary the length of time theliquors shall be sub ect to'the converting temperature and thereby varythe degree of conversion; and finally in neutralizing the acid in themixture b means of a suitable re-agent, approximate the end of thecolumn, or just prior to this.

For the better elucidation of my process I show in accompanying drawinan apparatus and describe the method 0 using it for practicing myprocess.

The vertical cylinder A is the converting column vessel. In it arecontained a number of horizontal perforated diaphragms 'n, n, &c., ofapproximately the same diameter as the interior of the cylinder andmixture at V y at the time it leaves equally spaced one above the other,the internal construction. Through the bottom lowest diaphragm a littleabove the bottom of the heater opens a live steam pi e T of thecylinder, and the uppermost one a which is fitted wlth a hand valve w. nthe little below the top of the cylinder. A disheater alittle above thebottom is a perfocharge ipe D, shown axial in the figure, exratedhorizontal plate g just above which tends 'rom below the lowestdiaphragm there opens into the eater the pipe h where it is fitted with.the inverted cup u up which connects to the discharge nozzle 0 throughthem all and through the top of the centrifugal pum P. From the top ofthe cylinder and leads into an empty tank the heater H, a disc arge pipeb leads into 0 T, which has an outlet above through the the convertingcolumn cylinder A above the pipe h, which leads into a spray condenserupper diaphragm in the same. This pipe is or heater H, hereinafter morefully defitted with a thermometer for indicating the scribed. Below, thetank T has a drain pipe temperature of the liquid flowing from the t,which leads down into and nearly to the heater into the cylinder A andwith a check 5 bottom of the sealing tank Twhich tank valve 1: whichopens toward the cylinder A. has an overflow pipe 25. The discharge pipeThe mode of using this apparatus in the D is fitted with a suitablevalve d. A pipe practicing of my process is as follows: Air D fittedwith a valve leads from the bottom is first driven from the system byopening of the cylinder A and serves for draining the valves d, '0, and0' respectively in the 20 the same if desired. pipe D, vent pipe V andvent pipe 0, the

C is a steam pipe which opens into the latter ofthe heater H, and thenadmitting cylinder below a number of the upper diasteam into the bottomof heater H through phragms, but above the level to which the the livesteam pipe W by opening the valve converting column of liquor will inpractice to. When the pipes D, 2), and 0 grow hot 25 ever rise ashereinafter described. The pipe due to escaping steam the air may becon- C is fitted with a hand-valve a and also with sidered as expelledand the valves in the a pressure reducing valve 0. The cylinder saidpipes closed. The hand valve 0 on the A is provided with safety valve S,pressure live steam line-C to the converting column age G, air vent pipeV, with valve '0, leadcylinder A is now opened, and the auto- 30 mg intothe pipe D beyond the valve cl and matic pressure reducing valve 0 isset to with provisions for indicating the height of maintain a steampressure in the cylinder liquor in the cylinder, such as the gage glasscorresponding to the desired converting tem- R on the side of thecylinder. A small test perature say 280 Fahn, or a little above pipe Ewith valve 6 leads from the discharge that. The safety valve S is setfor a little 35 pipe D at a point below its valve d into the above thispressure and the centrifugal tank T. Between its valve 6 and the pipe Dpump P is started. The mixture of starch is a small branch pipe E fittedwith a valve water and acid (mixed in pro ortions which 6 and openinginto the atmosphere. A small are kept preferabl practical y constant) ispipe J, fitted with valve 7', leads into the cylnow allowed to ow intothe top of the 40 in er below the lower diaphragm in the heater Hthrough the pipe h, by opening same, and immediately under the invertedthe valve W, at a constant rate regulated by cup u of the discharge pipeD. means of said valve-which will pass the The spray condenser, orheater H consists wished for quantity of material through the of avertical cylinder, closed top and bottom, system er unit of time. Thestarch iqnor 4 shown in vertical axial section in the drawpasses rom thebottom of the heater H ing, containin a horizontal erforated through thepipe h into the centrifugal plate 32 near t e top upon whic deliverspump P, which delivers the liquor as fast through the top of the heaterthe liquor as it comes through the pipe h into the botconducting pipe hwhich is fitted with a tom of the heater H. The centrifugal 50 handvalve 0 and leads from a source of pump is so proportioned and ismaintained supply of the mixture of starch, water and at such a speed aswill do this and deliver acid which is to be treated in the apparatusthe liquor under such a pressure as will being described. From thebottom of the force it up through the heater H into the heater H a pipek leads to the suction of a 'converting column cylinder A against the 55hi h pressure centrifugal pump P. Into the ressure in the latter. Assoon as the starch si e of the heater a short distance above the iquorbeginsto enter the bottom of heater bottom leads the pipe h, from thepressure H, live steam is turned into the bottom of reducing tank T.From the heater just bethe heater through the pipe W by means of low theperforated plate p leads a vent pipe the valve w which is regulated sothat the w 0 having a valve 0. starch liquor passes from the top ofthe His a heater in which high pressure heater H through the pipe I) andcheck steam is used for heating purposes. It is a valve 12 into cylinderA at or a little below vertical cylinder closed top and bottom: It theconverting temperature say 280 Fahr. is shown in vertical section fromthe bottom which corresponds to about 35 pounds pre..-

% for ashort distance upward to disclose its sure above atmospheric. Theheated acidu- 13o lated starch liquor flows on to the upper perforatedplate in the cylinder A at a constant speed, VlZ. that at which it isdelivered into the heater H through the pipe h. The heater H is soproportioned in size with respect to the norma flow of starch liquorthat the latter will be in it only long enough to be convertedpartially, part of the .convertingto be done in the cylinder A. Ifconditions are maintained constant as to rate of flow of the liquor andthe quantity and pressure of steam deliv- -ered into the heater H, theliquor will enter the cylinder A at a practically uniform state ofconversion.

When, in putting theapp'aratus into service, as is now being described,the starch liquor enters the cylinder A at the top and it falls throughthe perforations from diaphragm to diaphragm until it reaches the bottomof the cylinder. In falling through the atmosphere of steam in cylinderA, it is brought to the desired temperature by the latter. The valve inthe test branch pipe E is kept open. This permits the liquor to rise inthe dischargepipe D as soon as its lower end is covered with thestarchliquor. The discharge valve d is kept closed, and the level of. theliquor consequently rises in the cylinder to form the converting columnof liquor. the liquor flowing from the branch test pipe E shows by aproper testing reagent that the desired degree of conversion of thestarch liquor has been reached. This indicates that the liquor at thebottom of the converter, or to be exact, at the top of the dischargepipe Dhas been subjected to the temperature long enough toeffect thedesired degree of conversion. The valve d in the discharge pipe D is nowopened 'sufliciently to maintain the level, of the liquor where it waswhen the adequate reaction was obtained. If this be done, the liquorflowing from the pipe D will all have been-in the converting column thesame length of time, namely the time which was required to fill thecylinder up to the said level, say to the level Z, and the liquorflowing out will be all of ractically the same degree of conversion,that is assuming the rate of delivery of the starch liquor into thecylinder, and its acidity andalso the temperature in the convertingcolumn to all j remain constant. This latter will be the case so long asthe liquor added to the column from above is of a constant temperaturefor no heat is added to the converting column nor any taken from itexcept such as may be lost by conduction through the walls of thecylinder which may be rendered nil by a suitable-non-conducting coveringaround the surface of the cylinder.

The perforated diaphragms serve to evenly distribute the starch liquorover the surface of the converting column of liquor leaving a good It ispermitted to thus rise until in the cylinder, to cause a uniform flowdownward of the liquor from the top'of the column to the outlet at thebottom of the same, and to prevent the-agitation of the surface of theliquor to any considerable depth by the falling of the liquor upon theuniform will be the movement downward of the column of liquor throughoutits entire cross section, the less will be the agitation of the liquorcolumn at its surface and the less' will be the danger of mixture of anyportion of the movlng converting column of liquor with the portionswhich next precede or next follow it in the column, something to beavoided in the interest of uniform conversion.

While the apparatus is in service the vent valve 0 is left slightly opento permit of the escape of air and incondensable gases which mightcollect at the p of the converter cylinderA.

J is a mg column a solution of the re-agent (usually carbonate of soda)used for neutralizing the acid in the converted liquor. It-is mostconvenient that this solution be of constant strength and be deliveredinto the converter at a constant speed. The solutionthus deliveredthrough the pipe J mixes with the acid liquor and passes with it upthrough the discharge pipe D, and into the tank'T.

The rateof inflow of the neutralizing solution is regulated by suitablemeans as by the hand valve 7' so as-to produce in the outflowing liquorthe desired conditions respect to neutrality. The liquor in theconverting column is, with a view to quick con- 'version, preferablykept at a temperature considerably above 212 .Fahr., say at 280 Fahn,and at the corresponding pressure of 3.5 pounds above atmospheric. Theconwith pipe for delivering into the cylinder below the lower diaphragmin the convert- -lair verted liquor on entering the tank T in which thepressure is lower, say atmospheric, flashes in part into vapor, whichvapor escapes from the tank through the outlet pipe 71, into the heaterH in'which it heats more or less the incoming cold starch liquor whilethe converted liquor escapes through the outlet 23 into the sealing tankT and thence escapes by the overflow t.

Neutralization of the acid in the converted liquor may be effected afterthe latter leaves the cylinder A, but in that case the escaping liquorand vapors are acid and are destructive to metal pipes and apparatus.*or this reason I neutralize the acid While the liquor is still underpressure.

While the apparatus is in operation the valve 0 in the pipe E is keptslightly open so that there is always a flow of liquor through the pipeE from the discharge pi e D into the tank T. This permits samp les beingtaken at any time from the branch test pipe E which will exactly show,if tested, the degree of conversion of the discharging liquor.

Assuming constancy with respect to other conditions, namely-acidity,rate of flow of liquor through the converting column and temperature 1nthe latter, the degree 0 conversion in the liquor issuing fromthetdischarge pipe D Wlll vary with the length or depth of theconverting column of lnpuor in the cylinder. For example, if the sur aceof this column is caused to stand at the level Z and the conversion isright for the non-crystallizing product sold as glucose, the conversionwith the surface of the column held at some higher level Z will beproper for the solid product sold as grape sugar The level of thesurface of the liquor column may be raised by closing the valve d in thedischarge pipe D until the level is raised to the desired height by theinfiowing liquor, and then opening the valve 05 to the degree whichmakes the outflow of liquor equal to the inflow as indicated by thelevel remaining constant. The level of the liquor is lowered by openingwider the valve d until the level falls to he point desired, and thenclosing the valve until the level remains constant. It is' obvious that,maintaining a constant volume or height of converting column of liquorin the cylinder and a given temperature, the degree of conversion may bevaried by increasing or lessening the rate of inflow of the acidified 1iupr through the converting column since t ey respectively lessen orincrease the time the acid liquor is in the converting column andsubject to its temperature.

The results obtained by my process contrasting with those obtained bythe old intermittent method of converting starch, are the practicallyidentical degree of conversion of every particle of the starch, theuniform draft on the steam supply and other converting temperature, withonly a sewer advantages which usually attend a continuous process ascontrasted with an intermittent process.

The apparatus shown in the drawin I pur ose moor orating and claiming inoidier app ications or Letters Patent.

I now claim as of my invention:

1. The process of converting starch into its derivatives, dextrin,glucose, etc., consisting in mixing the starch with water and acid toform a mixture suitably mobile and acid; in passing this mixture with aconstant rate of flow through heating devices and heating it thereinqulckly to the desired converting temperature with only a partialconversion, if any; in passing the heated mixture as a uniformly movingcolumn through a retainin vessel to complete the conversion desired ythe heat stored in the mixture; in adjusting the time the mixtureremains in the column so as to produce the.

degree of the conversion desired; and in adding the neutralizing agentcontinuously and in proper quantities to the liquor while still underthe converting pressure and tem perature and just prior to its releasefrom same.

1 2. The process of converting starch into its derivatives dextrin,glucose, etc., consisting in mixing the starch with water and acid toform a mixture suitably mobile and acid; in passing this mixture with aconstant rate of flow through. heating devices and heating it thereinquickly to the desired artial conversion, if any; in passing the eatedmixture as a uniformly, moving column through a retainin vessel tocomplete the conversion desired y the heat stored in the mixture, and inadjusting the time the mixture remains in the column so as to producethe degree of conversion desired.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

S. MORRIS LILLTE.

Witnesses:

JOHN J. WALTER, COLIN D. SMITH.

